Some old test URLs not working?

Hi there,
I often copy/paste my test-result URLs into emails or bookmark them. It is easier to re-run the test…

Some URLs are really old (over 3 years) but still work: WebPageTest - Running web page performance and optimization tests...

Some URLs are rather young and do not work any more: WebPageTest - Running web page performance and optimization tests...

→ Which result URLs “stay” and which results break?
(or can I change the URL to show me the results for all test-URLs?)

thanks for any help!